Methods and apparatus to retard or prevent the oxidation of foods have become particularly advantageous in retaining the condition and therefore, commercial value of certain foods. More particularly, when heated, fats within foods oxidize and cause the condition of such foods to degenerate.
For instance, when nuts and seeds that generally contain large amounts of fats are heated by a treatment such as roasting, etc., the fats begin to oxidize, which causes abnormal odor and deteriorated flavor, thus lowering the commercial value of such foods. Since oxidation will continue through the generation of peroxidized lipids caused by the presence of oxygen, it is necessary to eliminate such oxygen to prevent the deterioration of foods, such as nuts and seeds.
Conventional methods to retard or prevent oxidization of foods include the sealing of an oxygen-removing agent within the food's packaging container; replacing the air within the container by an inert gas such as nitrogen or carbon dioxide gas, etc.; and producing an oxygen-free state by vacuum packing. Also typical of such conventional methods is the addition of an anti-oxidant such as tocopherol.
Conventional methods fail to provide a cost-effective workable solution to retard or to prevent oxidization of food such as nuts and seeds. For instance, sealing of an oxygen-removing agent within the food's packaging requires the combined use of gas barrier film that increases packaging costs. Moreover, considerable effort is required to control the effectiveness of the oxygen-removing agent.
Conventional methods of gas substitution packaging and vacuum packaging require costly equipment and costly set-up expense. Furthermore, with either gas substitution or vacuum packaging, once a container is opened, the entry of oxygen counteracts the oxidation-inhibiting effects of treated products maintained in an oxygen-free state or in a nearly oxygen-free state.
Conventional methods of adding anti-oxidants, although initially effective, later fail when the anti-oxidants naturally change and become ineffective. Hence, such agents are generally inappropriate for long-term preservation of foods such as nuts. Furthermore, it is difficult to uniformly penetrate and distribute an anti-oxidant within solid nuts. Additionally, for some types of nuts, the amount of anti-oxidant distributed within the nuts varies even within the same lot of nuts.
As a result, there has been a longfelt need for a reliable, cost effective method and apparatus for treating raw food material such as nuts and seeds so as to make them oxidation-resistant.